When I first moved to Vermont in 1987, I was told in no uncertain terms that I should give up any idea of growing rhododendrons or roses at my new home. The winters were simply too cold.
Just shy of thirty years later, rhododendrons and roses grow in abundance here in St. Albans, and a 2008 article in USA Today complained that the growing zone map issued by the USDA was no longer a reliable source:
The map doesn't show, for example, that the Southern magnolia, once limited largely to growing zones ranging from Florida to Virginia, now can thrive as far north as Pennsylvania. Or that kiwis, long hardy only as far north as Oklahoma, now might give fruit in St. Louis.
Magnolias in Pennsylvania and kiwis in St. Louis? Who'd have thought...?
While the current crop of Republican presidential hopefuls may be in full climate science denial, a brand new USDA zone map confirms that a general warm-up has indeed been in progress for some years now.
So that we might better appreciate the significance of the changes, the Arbor Day Foundation provides their own handy interactive map on which we are invited to track the northward shift of climate zones clear across America.
And, anticipating release of the new USDA map, forestry writer Cristina Santiestevan wrote in 2010 that
The type of climate we have for plants now is what we had 20 years ago, but roughly 200 miles to the south," explains Katharine Hayhoe, a climate scientist at Texas Tech University who develops models to predict future climate impacts around the country. In other words, the hardiness zones on the old map are now off, in some cases by as much as 200 miles.
She included her own mapped projections of forest impacts due to climate change over the next 90 years and concluded:
Ultimately, climate change will draw new lines between species and ecosystems. Some changes may be subtle and hard to notice, such as the gradual decline of coastal redwood forests over the coming centuries. Other changes will be hard to miss, such as the absence of blazing sugar maple trees in much of New England's autumn landscape.
And, if her projections prove correct, long before the sugar maples disappear entirely, their economic value to Vermont will shrivel and disappear. What happens then to the "Vermont Brand?"
Every year, as the color fades and the syrup dwindles, we will be painfully reminded not of nature's renewable miracles, but of her ultimate fragility at the hands of a reckless and insatiable species. |
